Predicting post-earthquake settlement of river embankments using parametric numerical

Department of Architecture and Civil Engineering, National Institute of Technology, Kumamoto College, Kumamoto, Japan

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

River embankments are critical flood control structures that protect human lives and property. To ensure safety during flood events, appropriate maintenance measures against seepage and erosion are required. In addition, embankments must maintain sufficient seismic performance to preserve their functionality after earthquakes. Currently, seismic safety assessments commonly rely on two-dimensional numerical analyses to predict post-earthquake settlements. However, these analyses are time-consuming and costly, which limits their applicability in preliminary evaluations. This study aims to develop a simplified prediction method by establishing a settlement prediction chart based on parametric analyses. Using numerical methods consistent with those applied in practical seismic assessments, a series of parametric simulations was conducted by systematically varying key factors influencing embankment settlements, including liquefiable layer thickness and liquefaction strength ratio. Based on the simulation results, a settlement prediction chart was constructed to estimate post-earthquake settlements under various embankment conditions. The validity of the proposed table was examined through deformation analyses of actual river embankment cross sections damaged during past earthquakes. The results showed that the predicted settlements were generally consistent with numerical analysis results, even for embankments with complex geometries. The proposed prediction chart can serve as an effective screening tool in seismic assessments, enabling efficient evaluation of levee performance and supporting decision-making for seismic countermeasures in river management.